Hoses manufactured with outer helical PVC, nylon, or other plastic-like polymer rod reinforcements are known in the art. Such hoses are also known as drop hoses. Drop hoses are mainly used for the transfer of various fluids, such as gasoline, petroleum based products, chemicals, food products, etc., in tank truck applications. Drop hoses, and similar corrugated hoses, are made by several different manufacturing methods, including those disclosed by U.S. Pat. Nos. 4,383,555, 4,471,813, 4,304,266, 4,012,272, and 3,938,929 and disclosed in WO97/24543. The hose ends are generally later coupled with cam and groove fittings and band clamps.
Because of the need for a tight fit between a fitting and the hose, the outside diameter of a fitting shank and the inside diameter of the hose are almost identical; the shank is usually a bit larger than the hose ID. The slightly larger shank OD results in deformation of those portions of the hose that are in contact with the shank. Thus a certain force is required to insert the fitting shank into the hose. The force required to insert the shank into the hose increases if the hose is reinforced with a rigid, non-deformable material such as the outer helical PVC rod. To provide the necessary force or to reduce the required force, it is known in the art to apply lubricants to hose, to attempt to soft the PVC prior to insertion in the hose, or apply greater force to the fitting to ensure a proper insertion. All of these methods are time and labor consuming and may be detrimental to the hose or the fitting.
The configuration of the outer corrugations can also make the insertion of the fittings into the hose bore difficult and make it difficult to install the band clamps over the plastic spiral wire and achieve a leak proof connection without band distortion and damage to the hose or fitting. Over the years, aids have been developed to overcome these situations. One such aid is to place a piece of rope between the outer corrugations of the cover to achieve a flat surface at each end of the hose that will make it easier to install the band clamps and prevent distortion. Another aid is the use of a “banding coil.” A banding coil is a separate spring or coil made out of a plastic-like material that is either screwed or wrapped on the cover and fills the corrugations created by the outer helical wire at each end of the hose. The result achieved by the banding coil is the same as the rope, which is to end up with a flatter surface to install the band clamps. Another aid is the use of a rubber-like sleeve that is slipped over the ends of the hose that also attempts to create a flatter surface.
The present invention of forming a drop hose with soft cuffed ends eliminates the known problem in the art and eliminates the use of external aids as described above in coupling this type of hose. Many other advantages also arise from the present invention, including easier insertion of the fitting into the hose, reduced labor in coupling the hose, better coupling retention, and a likely reduction of necessary inventory for hose distributors.
Corrugated rubber or plastic hose with cuffed ends are disclosed in the following patents. U.S. Pat. No. 4,099,744 discloses a hose end formed flat with no corrugations. U.S. Pat. No. 5,398,977, U.S. Pat. No. 5,497,810, and EP 330894 disclose a plastic cuff inserted over the corrugations. U.S. Pat. No. 3,640,312, discloses an extruded hose end formed without corrugations and U.S. Pat. No. 4,456,034, U.S. Pat. No. 4,996,741, U.S. Pat. No. 4,996,20, U.S. Pat. No. 4,295,496, and U.S. Pat. No. 4,669,508 all disclose extruded or rubber corrugated hoses with non-corrugated ends which are internally reinforced by helically extending wires placed within the extruded or preformed corrugations. However, the corrugations of these hoses are formed by the extruded layers or by internal helical means, differing from the external helical reinforcing means of the conventional drop hoses. It is the presence of the external helical reinforcing means of the drop hoses which has created the need for the external aids and high force required to apply fittings to the drop hoses.
However, in the drop hose of the present invention, the corrugations are solely formed by the helically extending outer reinforcement, and the base hose material has a constant internal diameter. While forming cuffs on hose ends is known in the art and the need for a constant outer diameter at the end of drop hoses to provide the hose with fittings has long been recognized in the art, as evidenced by the numerous types of aids used with conventional drop hose ends, forming a drop hose with cuffed ends in the manner of the present invention has not been appreciated or recognized. The present invention is directed toward a solution of a long felt problem in the art and provides the many benefits listed above.